Homer brooke



PATENTED JAN 25 1870 expedited 'g plunger or iuted gieten @am can.

Hour-1R BROOKE. or

new yYORK, N. Y.

Laim Parmi No. 99,145, amd January 25, 1ero, v

' mpnovmmnr ne rm:

. M Ammaortmn or nrsu'na'rons. ron anunciara-rows n. schedule reame u 1n um@ Lenen pasen: ma mung pm of u 'um To all whom it may concern Be it known that I, Homin Bnocxn, of the oity,

county, and State f New York, have invented a new ing an. insulator.

Ligure 3, a planof the mould, with insulator there in.

Figure 4, a view, in perspective, of the insulator, to the innuuietme oi which my improvement relates.

Similar Ietfeisot' reference indicate corresponding parts.

M y improvement more especially relates to the manufactureof glass insulators, formed with a countersink and hole or recess at' the base of the countersink, with a screw-thread cut in it.

Great diticulty. has been expereucediu the manufacture'ofsuch articles by the process which has heretofore obtained,'of forming the insulator, countersinking, and making the hole and cutting the screw-thread therein, by one and thc .same operation, through the agency of a screw-press. This is both a slow and imperfect process, causing an objectionable vamount of heat (which necessitates stoppage and cooling) to bc.

communicated to the plunger, ou account of the long retention of the'V latter within the glass, as necessary tocut the screw-thread, over o1' abovoaud iu addition to melely forming the insulator, and pressing the countersink and-hole therein; and is, furthermore, objectiouable on account of the liability of the glass to be;

rotated iu the mould, which makes. the insulator .stn'ngy or cordy. By my improved process, I rst.for|n the, insutor, and make the hole, or countersiuk andv hole therein; by the action'ot' a lever or quick-press, andbefore the glass has'set in the mould, transfer the latter, with' the hot insulator in it, under a slcwor screwpress, to cut or form the thread in the hole of the in.

suiator; This latter press hgs a retaiuer'on its plunger,

` to preserve the shape of the insulator, while thescrewthread is being cutor formedin its hole, said retainer,

preferably being detachable to meet wear and renewal. Inthis way the manufacture cf Ascrew-insulators is and improved, excessive heating of the plungers 4 being avoided, and a most pertact insulator produced.,

having .'sereu-threads in their In the accompanying drawing- A represents the insulator.'

b, its countersink;

c, its-hole; and

d, tho screw-thread formed therein.

B is the mould inwhich the hot glass inl pnt, and that is iirst placed under the plunger and former of a quick or lever-press, O, to shape the insulator, and form vthe countersink b and hole c therein. l

This is a quick operation, and does not give time for the heating of the plunger or ffm-mer, nor allow of the glass set-tingjn the mould, which, with the hot insulator in it, is then transferred nndera screw-press,

e though comparatively slow, is much quicker than if it had the Whole work to perform of forming, recess'ing, and threading, instead of having only the scre.wthread d to produce, in the already-formed hole o, as is here the case, and whereby excessive heating of the plunger or-its tap attachment is avoided. The division of the work between the presses likewise gives pause or rest to them. 4

lo prevent injury to the moulded insulator, while the'screw d is being formed in it, the press D is made with, or has iitted ou it a for|n-re t-aiuer, E, which its the countersink b, previously pro. duced by the first press c, and which carries or is made with a screw-extension or tap, e, to produce the screwthread d in the insulator. This retainer E 'it 'is advisable-to make detachable, as represented in the drawL ing, by giving it a socketed connection with the plunger,

,and securing it by a locking-ping to allow of its being iuterchanged or renewed, as .wear or other circumstances may require.v l What is here claimed, and desired to be secured by Letters Patent, isl. .lhe process of manufacturing' glass insulators, ingthemv, and making the cavity-or hole therein by then transferringthem,.before setould, to or under a second press, D, that Iproduces the screw-thread in their interlor, substantially as specified.

2. The screw-press D, having its plunger tted or provided with a forxh-retainer, E and screw-tap e, for operation on the heated glass in the mould, after the same has been shaped or formed, externally and internally, byprevious pressure, essentially as herein set' forth.

' f HOMER BROOKE.

Witnesses:

EREDJHarNEs, .nuns J. CAMPBELL plunger .of the i interior, by first` form- 

